1. Field of the Invention
The present invention relates to computer systems. More particularly, the present invention relates to a system and method of verifying the authenticity of dynamically connectable executable images.
2. Description of the Related Technology
New object models now provide for the dynamic integration of software applications at run time. For example, Windows, an operating system licensed by Microsoft Inc., allows for the dynamic integration of a software application with a dynamic link library during the execution of the software application. Upon a user request for the execution of the software application, a program loader copies a “disk image” of the application from disk storage to main memory to create a “process image.” The disk image refers to the executable image before it is loaded, whereas the process image refers to the executable image after it is loaded in memory. Both the disk image and the process image typically include a fix-up section that identifies which portions of the software need to be fixed-up to reference the dynamic link library at run time.
Significantly, after loading, the process image is different then the disk image. As such, a checksum that had been prepared with respect to the disk image would no longer match the checksum of the process image, even if the process image had not been improperly tampered with.
Therefore, there is a need for a system that can verify the identity of a software application in a dynamic loading environment. In particular, the system should be able to determine whether a software application that has been dynamically connected to another data object has been tampered with subsequent to the execution of the software application.